I made a drum smoker with a friend of mine who happens to be a very good cook. In the past he's slaved for hours over a gas grill and smoker boxes trying to get his ribs just right but now it's much easier to cook them.
The smoker has a controller that spins up a fan to keep the temperature inside the smoker at the desired cook-point. The controller is an Arduino running the standard PID software. The hardest part for us was creating the charcoal basket. I taught myself to weld (poorly) and made the basket out of expanded steel.
There are other Instructables on making a drum smoker (I based some of my construction on this one) so I'll just post my pictures.